Change search
ReferencesLink to record
Permanent link

Direct link
Biogas Production from Lignocelluloses: Pretreatment, Substrate Characterization, Co-digestion and Economic Evaluation
University of Borås, School of Engineering. (Swedish Centre for Resource Recovery)
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Sustainable development
The content falls within the scope of Sustainable Development
Abstract [en]

Biogas production from organic materials can be used as a renewable vehicle fuel, provide heat and generate electricity and can thereby reduce the greenhouse gas emissions. This thesis focuses on the biogas production based on lignocelluloses. There is an abundant availability of lignocelluloses, constituting 50% of the total biomass worldwide. However, the biomass recalcitrance limits the microbial degradation as well as the biogas production from these types of materials. In the present work different pretreatment methods have been performed in order to decrease the biomass recalcitrance and improve the biogas production. Steam explosion pretreatment, together with the addition of sodium hydroxide and hydrogen peroxide, has been performed on lignocellulosic-rich paper tube residuals. The pretreatment has resulted in methane yields of up to 493 NmL/gVS, which is an increase by 107% compared with untreated material. Furthermore, the use of an organic solvent, N-methylmorpholine-N-oxide (NMMO), was evaluated as a pretreatment method for spruce (both chips and milled), rice straw, and triticale straw. The NMMO pretreatment resulted in 202, 395, 328, and 362 NmL CH4/g carbohydrates produced of these substrates, respectively, corresponding to an increase of between 400-1,200% compared with the untreated version of the same material. Moreover, the paper tube residuals have been co-digested with an unstable nitrogen-rich substrate mixture, mainly based on municipal solid waste. The addition of the lignocellulosic-rich paper tubes in a co-digestion process showed stabilizing effects and prevented the accumulation of volatile fatty acids with a subsequent reactor failure. Additionally, synergistic effects have been found leading to between 15-33% higher methane yields when paper tubes were added to the co-digestion process compared with the yields calculated from the methane potentials of the two substrates. Substrate characterization analysis can be used to study the changes on the lignocellulosic components after the pretreatment, relating the changes to the performance in the anaerobic digestion. Increased accessible surface area, measured by the Simons’ stain and the enzymatic adsorption methods, as well as decreased crystallinity, determined by using the Fourier Transform Infrared Spectroscopy, can all be linked to improved biogas production after pretreatment. Finally, the NMMO pretreatment on forest residues has been financially evaluated for an industrial scale process design. The base case that was evaluated simulated a case where pretreated forest residues were co-digested with the organic fraction of municipal solid waste to obtain optimal nutritional balance for the anaerobic digestion. This process has been found to be economically feasible with an internal rate of return of 20.7%.

Place, publisher, year, edition, pages
Chalmers Tekniska Högskola , 2013.
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 41
, Doktorsavhandlingar vid Chalmers tekniska högskola, ISSN 0280-321X ; 3527
Keyword [en]
biogas, lignocellulose, pretreatment, anaerobic digestion, co-digestion, substrate characterization, economic evaluation, Biotechnology
National Category
Industrial Biotechnology
URN: urn:nbn:se:hb:diva-3654Local ID: 2320/12317ISBN: 978-91-7385-846-5OAI: diva2:877044

Akademisk avhandling som för avläggande av teknologie doktorsexamen vid Chalmers tekniska högskola försvaras vid offentlig disputation den 24 maj 2013, klockan 10.00 i KA,Kemigården 4, Göteborg

Available from: 2015-12-04 Created: 2015-12-04 Last updated: 2016-08-19Bibliographically approved

Open Access in DiVA

fulltext(6117 kB)127 downloads
File information
File name FULLTEXT01.pdfFile size 6117 kBChecksum SHA-512
Type fulltextMimetype application/pdf
spikblad(206 kB)18 downloads
File information
File name SPIKBLAD01.pdfFile size 206 kBChecksum SHA-512
Type spikbladMimetype application/pdf

Search in DiVA

By author/editor
Teghammar, Anna
By organisation
School of Engineering
Industrial Biotechnology

Search outside of DiVA

GoogleGoogle Scholar
Total: 127 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 70 hits
ReferencesLink to record
Permanent link

Direct link